Meal-treating process and apparatus



Jan. 8, 1957 N. F. KRUSE 2,776,894

MEAL-TREATING PROCESS AND APPARATUS Filed July 29, 1954 2 Smets-sheet 1 ACCESS DOOR l J ATTORNEYS Jan. 8, 1957 N. F. KRUSE 2,776,894

MEAL-TREATING PROCESS AND APPARATUS Filed July 29, ,1954 2 Sheets-Sheet 2 fgN V EN TORI.

United gStates Patent() ice ,.emed J,;,7,6189

MEAL-TREATING PROCESS AND APPARATUS Norman F. Kruse, Decatur, Ind., assignor to Central Soya Company, Inc., Fort Wayne, Ind., a corporation of Indiana Application July 29, 1954, Serial No. 446,519

12 Claims. (Cl. 9998) set forth a process vin which solvent-extracted Soybean oil meal containing solvent or other liquid is heated below the boiling-point of water, steam being introduced into the meal to condense steam thereon so as to bring the moisture content of the meal into the range of about 14 to 30% and then cooking the meal at a temperature above the boiling-point of water to produce a toasted meal. In the practice of the process, a shell or casing providing a vertical series of kettles has been employed, and steam was introduced into various of the kettles and passed upwardly through the meal in the different kettles. In such process, it was found that the steam employed in the lower kettles at least had to be reduced substantially, because when a large volume of steam was employed, flakes of the meal were carried from the topmost kettle into the condenser. As a result, it was necessary to introduce the major portion of the steam within the top kettle. There has long existed a need for a process and apparatus by which vapors and steam leaving the lower kettles could be effectively utilized in the uppermost kett'le without causing meal portions to be carried into the condenser.

An object of the present invention is to provide a process and apparatus overcoming the above described disadvantages and accomplishing the desired new results. A further object is to provide a method and means whereby steam and vapors from lower kettles may be effectively introduced into the uppermost kettle or body of meal by passing the same through the sides of the meal body over a relatively wide area. Yet another object is to provide means and apparatus whereby steam and vapors from a lower series of kettles may be continuously recovered in an annular channel or stream and passed upwardly through the uppermost body of meal for the removal of solvent and the condensing of steam and vapors to provide moisture for the meal. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawings, in which- Figure 1 is a vertical sectional view of apparatus embodying my invention and with which my new method may be employed; Fig. 2, a transverse sectional view, the section being taken as indicated at line 2 2 of Fig. l; Fig. 3, an enlarged vdetail sectional view of a jacketed bottom for a kettle and the sweep means employed therewith; and Fig. 4, a perspective view of a kettle employed in the-vessel shown in Fig. l.

In the illustration given, 10 designates an elongated 4vertical casing providing a treating chamber for the meal. The casing 10 is supported upon standards 11 2 carried by the base 12. A chute 13 extends into the upper portion of the casing 10 for supplying meal or other material to be treated. The top of the casing 10 is provided with an outlet 14 leading to a condenser or other suitable apparatus, as shown in greater detail in my Patent No. 2,585,793. i

Below the topmost kettle, which will be described in detail hereinafter, there are a series of vertically-spaced kettles 15, as shown in perspective in Fig. 4 and as shown in detail in Fig. l. Each of the kettles has a side wall 16 preferably provided with a manhole 17 and a cover plate 18 therefor, and each of the walls 16 is preferably cut away on opposite sides to provide vapor and steam passages 19. The side wall 16 of the kettle is closed at the bottom by a hollow steam jacket 20, which is shown in greater detail in Fig. 3. A flow passage or discharge passage, which may be in the shape of an inverted funnel, is provided by the casing portion 2l so that meal may constantly llow from one kettle into a kettle therebelow. Over each jacketed bottom 20 is mounted a sweep 22 which is fixed by means of a collar 23 and a setscrew 24 to the shaft 25 which is hollow to permit the passage of steam from the supply line 32. Following each blade of the sweep in the several upper kettles is a steam line 26 having at its rear steam discharge openings 27 so that as the sweep rotates, steam is delivered at the rear of the sweep blades, as shown more clearly in Fig. 2.

Steam may be introduced into each steam-jacketed bottom 2t) by any suitable means. As shown more clearly in Fig. l, a steam line 28 leads from a steam source and enters the jacket on one side while a steam outlet or condensate line 29 leads from the opposite side. lt will be understood that the lines 28 and 29 have suitable pipe connections for the delivery of steamand for the removal of condensate, etc.

The shaft 25 is driven by a motor and reduction gears mounted within the casing 30 on base 12. A steam connection for Ithe interior of the rotatable pipe 25 is provided at 31, and steam enters the pipe or shaft 25 through the xed steam inlet pipe 32.

At the bottom of the treating chamber, I provide a curved sweep 33 which is effective in sweeping the meal into the discharge pipe 34 through which the material is moved by a variable speed screw conveyor 35 regulated to discharge the same quantity of material being fed into the top of the unit, thus maintaining proper llage in the kettles.

Within the casing 1), I provide bracket supports 36 which are welded or otherwise secured to the casing 10 at their outer ends and which engage flanges 37 on the kettle Walls 16, whereby the several kettles are Supported in spaced relation within the chamber or casing 10. There is thus provided outside of the kettles an annular flow passage 3ft for the passing of steam and vapors from various kettles below upwardly toward the rst kettle.

I will now describe the rst kettle, which is the uppermost kettle shown in the drawing. The rst kettle is provided with a jacketed bottom 20 just as the other kettles, but instead of being provided with a vertical side wall, the kettle is provided with an apertured side wall 39, which extends outwardly and upwardly in the general shape of a funnel. The funnel wall 39 is provided with a large number of openings 4), each opening being covered by an inwardly and downwardly-extending lip 41. The lip 41 provides a shield which prevents the escape of meal into the annular passage, While at the same time directing upwardly-passing steam and vapors Within the annular passage 38 inwardly within the body of meal contained in the uppermost or first kettle. By utilizing the extensive area provided by the side walls 39 directly above the annular passage 38, I- tind that vast amounts of steam passed through the body of meal in the first kettle without tending to carry meal particles into the condenser.

`1 prefer ,to employabout midway Aof the -body ofmeal in the :first kettle, a steam box or jacket 42, theboxbeng provided with a plurality of steam openings 43., so that `a large amount of steam can be .discharged into the upper layer of the meal as it enters `the chamber for the Learly removal of solvent from the incoming Hakes. The Abox 42.is provided with a steam inlet pipe 44. A sweep 46 is `secured to the -shaft25 that is employed for moving the meal immediately above the box 42. If desired, a float .control device 47 may beiemployedto aid in maintaining -the :meal body at a desired level within the top kettle. :Since ,such mechanism is well known, a -detailed 4description herein is believed unnecessary.

The casing may be provided with manholes 48 and doors 49 therefor, and these are preferably aligned with `the kettle `openings 17 so that laccess ,can be readily had for repair and other purposes from `the exterioriof the casing, when this is desired.

If desired, exhaust or low pressure steam or mixed steam and solvent vapors may be introduced into the annular chamber or passage 3S through the line 50 or othersuitable pipe connection.

Operation `In the operation of the process and apparatus, feed is fed through the chute 13 into the top kettle, where it meets immediately steam from the box 42 for the re`- moval of solvent. At the same time, steam is delivered into the mass from the pipe following the sweep 22 over the jacketed bottom of the kettle. In addition to the steam thus introduced into kettle 1, I introduce through the side openings 40 of the funnel-shaped sides 39, a large volume of steam and vapors from the kettles below. The meal in the upper part of kettle 1 or the-top kettle is at a temperature below 212 F. The incoming steam is effective in removing solvent from the flakes lwhile at the same time steam is condensed upon the flakes to bring the moisture content up to from 14 to 30%, or above. In the operation described, I nd that `the vapors and steam coming up through the annular passage 3S and entering the mass of meal in the first kettle is particularly effective in supplying moisture to the individual flake surfaces in a metering type of action which distributes the moisture uniformly on the ake particles. As the meal descends through the outlets 21 from kettle 1 and succes sively through the kettles therebelow, the temperature of the meal is raised to a point above 212 to bring about a cooking or toasting of the meal, as is described in greater detail in my Patent No. 2,585,793. The heat for the meal 'within the lower kettles is provided by the jacketed bottoms 20. If greater heat is desired, the side walls 16 `of the kettles may be jacketed and supplied with steam in the same manner as the bottoms 20 are supplied with steam and this provision may also be made on the chamber 19.

I-have discovered that by providing vapor and steam outlets between the several ltettles through passages 19 `communicating with the annular chamber 38,fa large volume of steam and vapors can be transferred from the kettles'andmoved upwardly and discharged into the large body of meal in the'rst kettle. The large varea provided in the funnel-shnped sides 39 enables the vapors and steam to -be passed slowly but in large volume upwardly and through the topmost body or pool of meal, and by reason of such low velocity, it is found that there is no tendency for the flakes to `be carried over into the condenser. At the same time, the large area provided by the annular space permits the large volume of vapors and steam to pass slowly and effectively upwardly and through the meal, and such volume results in a substantial saving and reutilization of the heat of such vapors and steam. lSimilarly,the annular channel provides a jacket which lis 4 effective in heating the Aside walls of the kettles and Yinsuring uniform heating of the contents therein.

The vaporization of the bulk of the solvent in the rst kettle enables me to use a large amount of direct steam without overheating the Hak-es, and a large amount of steam is thus avilable for condensing upon the surface areas of the flakes to give each its proper content of moisture. Further, by passing the steam and vapors `from the lower kettles in an annular stream or channel into the side of the mass of meal inthe first kettle, I nd that quick and effective condensing occurs within the first kettle upon the various akes from which the solvent is being removed. In this step I prefer to increase the moisture content to a range of about 14% and up to about 25 although, if desired, the content of moisture may be raised to 30% or higher. Excellent results are obtained when the moisture is in the neighborhood of 15%-20%. As the meal passes through the compartmented cooker, the moisture of the flakes in contact with the sweep produces agglomerates, but while such agglomcrates are formed, it is surprising to find that the continued violent steaming removes substantially all of the residual solvent, while at the same time exerting a preserving `action on the vitamin B-l and the other nutritional ;factors, while developing new and valuable physical characteristics in the product. The protein present in the gmeal is altered `to give a higher nutritional value, and the agglomerates acquire a uniform golden color throughout. The meal increases substantially in density while retaining a very high thiamin content. By reason of the increase in density formed by the addition of moisture, there is more effective heat transfer to the interior `of the flake particle so that the cooking is more uniform throughout and there is a very slight difference between the temperature on the outer surface of the particle and that `within the linterior of the particle.

As stated above, in the first kettle and in the initial operations, rI prefer to keep the temperature of the meal ,below l212" F. so as to bring about a condensation of the steam, as the solvent is removed, and to increase Ithe moisture content of the meal by such steam con densation. In the following heating or cooking operation, `a desirable top temperature is between 225 and 26.5 F. I prefer to employ a temperature not above 300 F. The cooking is desirably, and more conveniently, done at atmospheric pressure, but it will be understoodthat higher or lower pressures may be employed.

The number of compartments may be varied considerably, depending upon the type of oil meal or other material being treated and upon the results desired. It is possible to operate the process upon solvent extracted loil meal from which the solvent has been alreadyremoved, but in this instance I prefer to add water or other liquid to the meal before it is subjected to the treatment described above.

While, in the foregoing specification, I have set forth a specific structure and method in considerable detail for the purpose of illustrating specific embodiments of the invention, it will be understood that such details of structure and `method may be varied widely by those skilled in the art without departing from the spirit of `my invention.

I claim:

l. In a processfor treating solvent extracted oil meal containing liquid, the steps of passing meal successively ,through vertically-spaced kettles, passing steam through themeal in the uppermost of said kettles to vaporize liquid from said meal, passing steam through the meal in the lower kettles of said vertical series, removing lsteam and vapors from said lower kettles, passing the same in an annular stream through the uppermost kettle, and condensing a substantial portion vof the steam upon ythe meal therein.

2. The process o-fclaim 1,in which the meal is soybean oil meal and the liquid contained thereby is a solvent.

3. In a process for treating solvent extracted oil meal -ontaining solvent, the steps of passing said meal through ,vertically-spaced kettles to maintain pools of meal therein, passing steam through the meal in the uppermost of said kettles to vaporize solvent therefrom, passing steam through the meal in the lower kettles in said series, removing steam vapors from said lower kettles, passing said removed vapors and steam in a stream enclosing said pools and into said uppermost kettle, and condensing a substantial portion of the steam upon the meal therein.

4. The process of claim 3, in which the bulk of the solvent is removed in the uppermost kpool of meal and said meal is cooked at a temperature above 212 F. in lower of said pools.

5. In a method for treating solvent extracted oil meal, the steps of passing the oil meal successively into contact with spaced pools of meal, introducing steam into the uppermost pool of meal to remove the bulk of the solvent from the meal, introducing steam into lower pools of said mean to remove vapors from the meal, removing excess steam from said lower pools and vapors therefrom, passing said removed vapors and steam outside of said lower pools, introducing the same inwardly vthereof through sides of said first-mentioned pool of meal and condensing a substantial portion of the steam upon the meal therein.

6. In material-'treating apparatus, a casing providing a vertical chamber, kettles in said chamber spaced inmunication between the kettles and said annular passage, y

means for heating said kettles, a top kettle having outwardly-inclined side walls provided with apertures communicating with said annular passage, and a sweep for agitating the material in said kettle.

7. The structure of claim 6, in which said uppermost kettle is provided with means for introducing steam into the kettle.

8. The structure of claim 6, in which said inclined walls of the uppermost kettle are provided with inwardly and downwardly-extending bahes covering said apertures.

9. In material-treating apparatus of the character set forth, a casing providing a vertical chamber, kettles in said chamber in vertically-spaced relation, said kettles being spaced inwardly from the sidesrof the casing to one kettle to another and in which sweeps move thek material into said passages.

l1. The structure of claim 9, in which the bottom walls of the kettles are provided with discharge passages and in which sweeps equipped with steam lines having apertures move the material into said passages.

12. In material-treating apparatus, a casing providingA a vertical chamber and equipped with an inlet chute at one endv and a discharge chute at the other, a plurality of kettles supported in superposed vertical relation within said chamber and in spaced relation from the sides of said chamber to provide an annular passage, -said kettles having openings therein for the escape of vapors and steam from the kettles into said annular passage, means for introducing steam into said kettles, openings in the bottoms of said kettles for the transfer of material from one kettle to another, a top kettle supported above said first-mentioned kettles and having an inclined side wall extending over said annular passage andprovided with spaced apertures therethrough, a steam chest mounted in said top kettle provided with steam outlets, and means for introducing steam into said steam chest for the discharge of steam into the upper portion of the material within said top kettle.

References Cited in the tile of this patent UNITED STATES PATENTS 2,254,867 Bonnotto Sept. 2, 1941 2,585,793 Kruse Feb. 12, 1952 2,669,032 Zimmerman Feb. 16, 1954 2,695,459 Hutchins Nov. 30, 1954 FOREIGN PATENTS 606,891 v Germany Dec. 13, 1934 

1. IN A PROCESS FOR TREATING SOLVENT EXTRACTED OIL MEAL CONTAINING LIQUID, THE STEPS OF PASSING MEAL SUCCESSIVELY THROUGH VERTICALLY-SPACED KETTLES, PASSING STEAM THROUGH THE MEAL IN THE UPPERMOST OF SAID KETTLES TO VAPORIZE LIQUID FROM SAID MEAL, PASSING STEAM THROUGH THE MEAL IN THE LOWER KETTLES OF SAID VERTICAL SERIES, REMOVING STEAM AND VAPORS FROM SAID LOWER KETTLES, PASSING THE SAME IN AN ANNULAR STREAM THROUGH THE UPPERMOST KETTLE, AND CONDENSING A SUBSTANTIAL PORTION OF THE STEAM UPON THE MEAL THEREIN. 